Dental instrument



Aug; 17, 1943.

o. G. MCKENZIE 2,327,203

DENTAL INSTRUMENT Filed Jan. 13, 1942 Patented Aug. 17, 1943 UNIT-ED STATE DENTAL INSTRUMENT V Olin G. McKenzie, Miami; Application January 13, 1942, Serial No. 426,623

7 Claims. (CI. 32 54.)

The invention relates to dental instruments and more particularly topower operated pluggers.

The primary object of the invention is to provide a simple and efiicient plugger construction which can be used in an ordinary drilling instrument, especially in the usual contra-angle hand piece.

Another object of the invention is to produce a plugger which can be inserted in place of an ordinary drill in a drilling instrument, and which will be caused to reciprocate by the drivin mechanism of the instrument.

A further object isto provide a plugger which can be used in the usual contra-angle or other drilling device by a simple chang in the latch thereof, requiring no change whatsoever in the body structure of the device.

Still another purpose of the invention is to produce parts for this purpose which can be given different angular positions so as to make a single plugging member serve in place of two or more.

An additional object of the invention is to pro- 7 vide a plugger formed of two parts, one adapted to be rotated in the same manner as the usual drill, and the other held against rotation; these two parts having cooperating cam surfaces on their adjacent ends to cause the second part to reciprocate when the first is rotated. In Connection with these parts there is used a special latch which holds the second part against rotation. A further feature of the invention is that this latch has all the functions of the usual latch, so that it can be used equally well to hold an ordinary drill when the instrument is to be used for drilling, and that the portion of the latch which prevents rotation does not interfere with the drilling action. Thus the latch need not be interchanged when the instrument is converted from a drill to a plugger, or vice versa.

Further objects and advantages of the invention will appear more fully from the following description, particularly when taken in conjunction with the accompanying drawing which forms a part thereof.

In the drawing: I V

Fig. 1 shows in side elevation a conventional type of contra-angle hand piece embodying my invention.

Figs. 2 and 3 are top plan views of the head thereof with the special latch in closed and open positions respectively.

Fig. 4 is a cross section on the line !4 of Fig. 1. Y

Fig. '5 shows the plugger parts of Fig. at'a right angle thereto. v r

Fig. 6 is aperspective view of the cam ends of the plugger parts. r

Fig; 7 is a' cross section on the line ll of Fig. 1; and

Fig.8 is a bottom plan view of a modified form of plugger for usein variable angular positions. Asshown in Fig. 1, the conventional contraangle piece 2 has a shaft Aadanted to-be driven in the usual manner. This shaft drives a'gear ii in the head piece '8'which is provided with a bore 10 to receive a drill. The hole in gear 61, has a flat I2 by which the'drill can be keyed thereto. The head 8 also has an overhanging portion l4 providing a slot I6. for'receiving an ordinary latch, which canibe held in placeby a screw it.

The special latch which is used has the parts of1the usual latch, namely a handle 29 engageable with the stem of theangle piece to prevent the latch from turning and to permit manipula;

tion thereof; and the fiat portion Z'Zhaving 'a notch 24 pivoted on screw [8 and thus"'capable of moving into the slot [6. This lat-ch has a downward extension 26 from the flat portion 22 and an inwardly turned end 28 with a notch 3Q having parallel sides, located below the end of bore I 0 in the head.

The upper part 32 of the plugger has its head portion shaped like the conventionaldrill, with a cut away portion 34 adapted .to fit through gear 8 and engage the flat [2. thereof so as to be'keyed thereto; and with a groove 35 into which the edges of notch 24 engage to hold this upper part in the head. On its lower end the upper part 32 hasa helical cam surface38.

The lower part has a portion of square or other polygonal section at 42 which fits within notch 30 and engages the edges thereof so as to be. prevented from turning, but being s'lidabl for a limited distance. Part 40 at its upper end has a helical cam surface 44 which engages cam surface 38 on the upper part 32. The bottom end of the plugger part is of. any suitable shape shown as a plain cylinder in Figs. 1 to 7.

The operation of this device is as follows: After the latch shown herein hasbeen substituted for the usual latch, by removing and replacing screw l8, thetdevioe may be used for either drilling or plugging. For plugging, the latch is opened to the position shown in Fig. 3 and the parts 32 and 40 are successively introduced from the bottom into bore Ill. By engaging the cam surfaces and turning part 40, part 32 may be turned until its head 34 moves into gear 6. Latch 22 is then closed to the position of Fig. 2 .and notches 24, 30 engage groove 38 and section 42 respectively to hold the parts in place.

When shaft 4 is turned to rotate gear 6 and part 32, the cam surfaces will obviously move part 46 downward and then release it for a return motion. As the plugger is pressed against the tooth, this will cause a series of forward movements of part 40 and will exert the normal plugging action.

For drilling, the latch is released, the parts 32 and 40 are removed, and a drill is inserted in the head. The stem of this drill will pass through notch 30 but will be freely rotatable therein so that the usual drilling operations can be carried out.

The plugger of Fig. 8 has an unsymmetrical or ofiset end portion 46. This can be, of course, disposed at any one of four different angular positions around its longitudinaltaxis, by varying its position in notch 30. In this Way a sin- Jle part can be made to serve the purpose of two, four or more pieces which are counterparts of each other but arranged at different angles of rotation.

While I have described herein some embodiment' of my invention, I wish it to be known that I do not intend to limit myself thereby except within the scope of the appended claims.

I claim: a

l. A dental plugger comprising a head forming a portion of a dental handpiece and having a rotatable member'therein, a first part having means engageable with said member for connecting the part thereto for rotation therewith, a latch permanently secured to and movable on said head, said first part and said latch having cooperating means thereon for releasably holding said first part rotatably in the head,

a second plugger'part, and cooperating releasably engageable means on said latch and said second part for preventing rotation of said second part while permitting sliding thereof, said parts having cooperating cam surfaces thereon whereby rotation of said first part causes recipro'cation of said second part.

2. A dental plugger comprising a head forming-a portion of a dental handpiece and having a bore therein, a rotatable member in said head i.

having an opening aligned with said bore, means to rotate said member, a first part insertable into said here having a portion capable of entering and extending through said opening, .said portion and opening being non-circular so as to key said part to said member, a latch carried by and movable on said head, the portion. of said first part which extends through said opening and said latch having cooperating means thereon for releasably holding said first part rotatably in the head, a second plugger part, and cooperating releasably engageable means onsaid latch and said second part for preventing rotation of said second part while permitting sliding thereof, said parts having cooperating cam surfaces thereon whereby rotation of said first part; causes reciprocation. of said second part.

3. A dental plugger comprising a head forming a portion of a dental handpiece and having a bore therein, a rotatable member in said head having an opening aligned with said bore, means to rotate said member, a first part insertable into said bore having a portion capable of entering and extending through said'opening, said portion and opening being non-circular so as to key said part to said member, a latch pivoted on said head, the portion of said first part which extends through said opening and said latch having cooperating means thereon for releasably holding said first part r0- tatably in the head, a second plugger part insertable into said bore having a portion of noncircular section, and said latch having a notch therein releasably engageable with said non-circular portion of the second part to prevent rotation while permitting sliding thereof, said parts having cooperating cam surfaces thereon whereby rotation of said first part causes reciprocation of said second part.

4. A. dental plugger comprising a head having a bore therein and a slot adjacent the top of the head intersecting said bore, a rotatable member in said head having an opening aligned with said bore, means to rotate said member, a first part insertable into said bore having a portion capable of entering and extending through said opening to a sufficient extent to enter said slot. said portion and opening being non-circular so as to key said part to said member, a latch pivoted on said head having a portion move ie into slot, the portion of said first part which extends through said opening said latch having cooperating means thereon for releasably holding said first part rctatably in head, second plugger part insertable into bore having a portion of non-circular section, and said latch having an extending portion provided with a notch releasably engageable with said nonciroular portion of the second part to prevent rotation while permitting sliding thereof, the adjacent ends of said parts having cooperating cam surfaces thereon whereby rotation of said first part causes reciprocation of said second part.

5. Equipment for converting a dental drill to a piugger,-comprising two parts having cooperating cam surfaces on their adjacent ends wheroh rotation of the first of the parts may cause recipiocation of the second part, the first part having means for keying it to a rotatable memher, and a latch adapted to be pivoted to a drill, said latch having two parallel sections spaced from each other, a first section and said first part having cooperating releasable means thereon for holding said first part ,rotatably in said drill, said second part having a portion of non-circular section, and the second section having a notch therein releasabiy engageable with said non-circular portion of the second part to prevent rotation while permitting sliding thereof.

6. Equipment for converting a conventional dental drill to a plugger, wherein the drill includes a rigid head having a passage to receive a burr shank and a driven rotatable member journalled therein and having a coupling element in said passage, said equipment comprising two parts having cooperating cam surfaces on their adjacent ends whereby rotation of the first of the parts may cause reciprocation of the second part, the first part having cooperating 11' ns for engaging said coupling element to be d ven thereby, and a latch pivotally secured to the rill 1 said first part and said latch havi- -c n for g said first part rotatably in the driil, and second part and latch having cooperating 1 sably en ageable means for pr vent-ing ro tation of said second part while permitting sliding thereof in said head passage, said latch being adapted to release said parts simultaneously.

7. Equipment for converting a conventional dental drill to a plugger, wherein the drill includes a rigid head having a passage to receive a burr shank and a driven rotatable member journalled therein and having a coupling element in said passage, said equipment comprising two parts having cooperating cam surfaces on their adjacent ends whereby rotation of the first of the parts may cause reciprocation of the second part, the first part having cooperating means for engaging said coupling element to be driven thereby, and a latch pivotally secured to the drill 10 part in said passage.

head, said first part and said latch havingcooperating releasably engageable means thereon for holding said first part rotatably in the drill, in the manner of and interchangeably with a burr, said second part having a portion of non-circular section, and said latch having a notch therein releasably eng'ageable with said non-circular portion of the second part to prevent rotation there of while permitting sliding of a portion of said OLIN G. McKENZIE. 

